Jones was known as "Sad Sam" for his mournful expression (and in memory of an earlier Sad Sam Jones), and also "Toothpick Sam" because he was always chewing on a flat wooden toothpick. In a pro career that spanned 21 years (1947-1967), Jones got his start in the Negro Leagues in 1947 and 1948. He played in the semi-pro Southern Minnesota League in 1949 before signing with the Cleveland Indians, where he could not break into the starting rotation. He finally got a chance with the Chicago Cubs, who traded Ralph Kiner for him.

Sam was in the majors for eight full seasons (1955-1962) and parts of four others (1951-1952, 1963-1964). He had his biggest years with the St. Louis Cardinals and San Francisco Giants between 1957 and 1960. One of the most similar players, Mario Soto, is an interesting comparison.